package org.apache.lucene.index;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;

/**
 * A {@link MergeScheduler} that simply does each merge sequentially, using the
 * current thread.
 */
public class SerialMergeScheduler extends MergeScheduler {

	/**
	 * Just do the merges in sequence. We do this "synchronized" so that even if
	 * the application is using multiple threads, only one merge may run at a
	 * time.
	 */
	synchronized public void merge(IndexWriter writer)
			throws CorruptIndexException, IOException {

		while (true) {
			MergePolicy.OneMerge merge = writer.getNextMerge();
			if (merge == null)
				break;
			writer.merge(merge);
		}
	}

	public void close() {
	}
}
